Send in a short writing sample showing you know how to form and support an argument. Then have an online introductory interview and have the test assignment (paid) explained to you. There are two people in the second interview and the interview is more formal. They also discuss the test assignment.

The whole process moved at great pace with no delays. From application submission to initial screening call took one week. Very knowledgeable and polite recruiter. No curveballs re line of questioning. It was along the lines of the standard ... recounting your experience and highlighting how it makes you a suitable candidate.